scholarly journals Effects of Spore Availability, Spore Germinability, and Shoot Susceptibility on Gall Rust Infection of Pine

Plant Disease ◽  
2001 ◽  
Vol 85 (11) ◽  
pp. 1193-1199 ◽  
Author(s):  
B. D. Moltzan ◽  
P. V. Blenis ◽  
Y. Hiratsuka

Temporal changes in three factors (shoot susceptibility, spore availability, and spore germinability) were evaluated to estimate their effects on the infection of lodgepole pine (Pinus contorta var. latifolia) by Endocronartium harknessii. Germinability of rust spores from sori free of hyperparasites remained above 80% during the growing season and thus would not have significantly limited infection. In contrast, there was a slight, but statistically insignificant, increase in estimated susceptibility as infection increased from 94% of maximum at 45% shoot elongation to maximum susceptibility at 90% shoot elongation. This was followed by a precipitous decline in estimated susceptibility to 57% of maximum when shoots were 95% elongated. Spore availability was 24% of maximum when shoots were 45% elongated, and thus may have been limiting at the beginning of the growing season. At the end of the growing season, spore availability declined prior to, or simultaneous with, the decline in susceptibility. The combined effect of both factors drastically reduced the number of infections estimated to occur once shoots are more than 95% elongated. As shoots elongated, relatively more infections formed higher on the shoot, supporting the hypothesis that periderm is important in limiting infection.

2005 ◽  
Vol 35 (6) ◽  
pp. 1314-1318 ◽  
Author(s):  
Peter V Blenis ◽  
Wuhan Li

Infection of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) by western gall rust has been shown to decrease with tree height and age, but the effects of those two factors have not been separated. Five replicate artificial inoculations were done on a total of 327 trees of different ages in two height classes. Temperature and percentage of spore germination at the height of inoculation, shoot development (stem elongation at the time of inoculation as a proportion of final shoot elongation), main stem leader length at the time of inoculation, tree height, and tree age were measured. Modeled percentages of infected trees and the number of galls per 10 cm of shoot length decreased by 85% and 88%, respectively, as tree age increased between 2 and 10 years, indicating the undesirability of early, aggressive precommercial thinning of lodgepole pine stands in areas where western gall rust is common. By controlling and (or) statistically accounting for inoculum, microclimate, and phenological factors, it was possible to demonstrate that changes in susceptibility with tree age are sufficient to account for the reduction in infection with tree height.


2010 ◽  
Vol 40 (12) ◽  
pp. 2333-2344 ◽  
Author(s):  
Christopher M. Wallis ◽  
Richard W. Reich ◽  
Kathy J. Lewis ◽  
Dezene P.W. Huber

Maximization of lodgepole pine ( Pinus contorta Douglas ex Louden var. latifolia Engelm. ex S. Watson) growth in a future climate with increased pest activity requires an understanding of the natural variability of quantitative resistance to disease. Foliar and bark secondary metabolites from different lodgepole pine provenances (populations) were quantified and correlated with severity of foliar diseases caused by Lophodermella spp. ( Lophodermella concolor (Dearn.) Darker or Lophodermella montivaga Petre.) or Elytroderma deformans (Wier) Darker and bark diseases caused by Elytroderma or Endocronartium harknessii (J.P. Moore) Y. Hiratsuka. Greater foliar concentrations of lignin, tannins, and some phenolics were associated with increased resistance to single or multiple foliar pathogens. Bark secondary metabolites levels were generally unassociated with resistance to bark diseases. Provenances appearing to originate in ecosystems where lodgepole pine are not the dominant species generally were more susceptible to foliar diseases and had less foliar defense-associated compounds than trees from areas where pines were the dominant species, yet clear trends proved to be elusive. Regardless, pine provenances with greater foliar levels of identified defense-associated compounds should be preferred seed sources for replanting forests in areas in which foliar disease is expected to be increasingly prevalent.


2006 ◽  
Vol 36 (4) ◽  
pp. 878-885 ◽  
Author(s):  
J M Wolken ◽  
P V Blenis ◽  
I Duncan

The probability of lodgepole pine (Pinus contorta Dougl. ex Loud.) having main-stem galls caused by western gall rust, Endocronartium harknessii (J.P. Moore) Y. Hiratsuka, surviving to rotation is unknown. To evaluate survival, 400 galled trees with at least one stem gall and 400 trees without stem galls were measured in 1992 in two precommercially thinned stands approximately 20 years old. The survival of trees was assessed in 2003. Nonlinear regression using iteratively reweighted least squares was employed to estimate the survival of galled trees as a function of the proportion of the main stem encircled by galls. Galls encircling >79% and >91% of the stem in the two stands increased the risk of mortality relative to non-galled trees, with the risk increasing steeply with percent gall encirclement; smaller stem galls did not cause tree mortality. The 11-year pattern of survival of galled trees was similar for infections that occurred on the main stem and those that had reached the stem from a nearby branch infection. Based on an earlier model of gall expansion, 38%–43% of stem-galled trees would be expected to survive until age 80. Scribing of stem galls to prevent their expansion does not appear to be a feasible management strategy.


1998 ◽  
Vol 28 (3) ◽  
pp. 478-484 ◽  
Author(s):  
Rong-Cai Yang ◽  
Narinder K Dhir ◽  
Leonard K Barnhardt

A total of 456 half-sib families of superior lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) trees found mostly in high-elevation natural stands in west-central Alberta were outplanted in 1990 at two geoclimatically different sites, Norris and Redrock, Alberta. The trials were measured at age 6 for survival, height, and incidence and severity of western gall rust (WGR) (Endocronartium harknessii (J.P. Moore) Y. Hiratsuka). Survival at both sites was very similar (85-87%). Mean family height at Redrock was almost 10 cm higher (60.5 cm) than that at Norris (51.0 cm). Mean family WGR incidence was 25% with a range of 0-76% at Norris, but only 1.6% with a range of 0-27% at Redrock. A similar site difference was also observed for WGR severity. Strong site x family interactions were detected for height growth and WGR infection. The interaction for WGR infection did not seem to involve a change in family ranks because there was very little contribution to the interaction variance from lack of perfect genetic correlation between the two sites. The contrasting patterns of family variation in WGR infection across the two sites may be the outcome of epidemiological (environmental) or genetic causes or both.


2006 ◽  
Vol 36 (5) ◽  
pp. 1059-1066 ◽  
Author(s):  
Isabelle Chuine ◽  
Gerald E Rehfeldt ◽  
Sally N Aitken

In this study we aimed to compare and explain the height growth performance of two contrasting pine species: lodgepole pine (Pinus contorta Dougl. ex. Loud) and western white pine(Pinus monticola Dougl. ex D. Don.). We compiled measurements of total height growth at different ages and shoot elongation phenology realized in several provenance test trials for 109 provenances of lodgepole pine and 54 provenances of western white pine. The response of shoot elongation to temperature was assessed using a phenological model fitted on provenance mean growth curves. Although total height growth followed the same geographic trends in both species, the response of shoot elongation to temperature was different between the two, with few (lodgepole pine) or no differences among provenances (western white pine) from diverse geographic regions. The temperature for which potential cell growth rate is 50% was 10.8 ± 0.13 °C (mean ± standard error) for western white pine compared to 5.26 ± 0.075 °C for lodgepole pine. Phenology did not explain growth performance differences among geographical regions in both species, which instead were explained by differences in the number of internodes set the preceding summer; provenances originating from stressful environments produced the fewest internodes, possibly due to reallocation of carbohydrates to stress resistance.


1998 ◽  
Vol 28 (3) ◽  
pp. 439-449 ◽  
Author(s):  
Harry X Wu ◽  
Cheng C Ying

Stability of 76 interior lodgepole pine (Pinus contorta ssp. latifolia Engelm.) provenances in resistance to western gall rust (Endocronartium harknessii (J.P. More) Y. Hiratsuka) and needle cast (Lophodermella concolor (Dearn.) Darker) was investigated from 19 and 23 sites in the British Columbia interior, respectively. Provenances, sites, and provenance by site interaction had significant effects on severity level of infection of both diseases. Susceptible provenances contributed mainly to the interaction. The resistant provenances to both diseases were very stable and essentially homeostatic across sites (regression coefficient approaching 0). Resistant provenances were concentrated in the jack pine (Pinus banksiana Lamb.) - lodgepole pine hybrid zone and adjacent areas, and provenances from the low-elevation interior wetbelt were also very resistant to needle cast. Geographic patterns of provenance variation revealed that the closer a lodgepole pine provenance is to the limit of jack pine distribution, the higher and more stable is its resistance to western gall rust and needle cast. The current multiple-site evaluation supports for the hypothesis that jack pine introgression influences pest defence in lodgepole pine and suggests genetic selection can be effective.


2003 ◽  
Vol 18 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Christopher Opio ◽  
Kona van Diest ◽  
Norman Jacob

Abstract Height to diameter ratio (HDR) has been proposed as an alternative to conventional procedures for assessing competition between crop trees and other vegetation. Yet HDRs vary throughout the growing season due to variations in the rate of change in height and diameter. There is an interest, therefore, in determining variations in HDR within a growing season (intra-seasonal changes) and the time of the year when measurements of HDR should be taken for operational purposes. HDR measurements were taken on five occasions at two lodgepole pine (Pinus contorta var. latifolia) sites in the central interior of British Columbia, from early May to late October through the 1999 growing season. Although the focus of the article is the investigation of intra-seasonal changes in HDR, we also compared August 1999 measurements with August 1998 measurements to determine the variation in HDR between growing seasons (inter-seasonal change). The study involved a completely randomized, one-factor experimental design, with replication over time. The removal of competing vegetation (known as brushing) was the factor. The design consisted of four levels of brushing, replicated three times on each study site. The results indicated that HDRs increased from early May to July and then decreased until October to levels equal to or lower than those obtained in August 1998. The highest HDR values were observed in control plots. The analysis of variance (ANOVA) with repeated measures indicated that treatment (brushing radius) and date of HDR measurement had significant (P < 0.05) effects on the intra-seasonal changes in HDR. The results suggest that HDR measurements should be taken either after mid-August, or before mid-May when changes in HDR are negligible. West. J. Appl. For.18(1):52–59.


2015 ◽  
Vol 45 (4) ◽  
pp. 411-421 ◽  
Author(s):  
Richard W. Reich ◽  
Jean L. Heineman ◽  
Amanda F. Linnell Nemec ◽  
Lorne Bedford ◽  
Jacob O. Boateng ◽  
...  

Site preparation can improve lodgepole pine (Pinus contorta var. latifolia Engelm. ex S. Watson) survival and growth; however, we lack information regarding possible interactions between treatment effects and the impacts of western gall rust (Endocronartium harknessii (J.P. Moore) Y. Hirats.) and comandra blister rust (Cronartium comandrae Peck). Mechanical and burning techniques examined over 24 years at a sub-boreal British Columbia site did not significantly increase rust infection rates or characteristics relative to an untreated control. Most infection occurred before age 10 years and at heights <2 m. By age 24 years, 22% and 10% of pine had sustained at least one western gall rust or comandra blister rust stem infection, respectively, but only 4% of western gall rust infected trees were dead, compared with 60% of comandra blister rust infected trees. Exploratory regression analysis of the relationship between tree volume and percent stem encirclement and infection height suggested that volume of 24-year-old pine infected with western gall rust averaged 8% less than the corresponding volume of uninfected trees. Over 24 years, estimated stand-level, rust-related volume loss was 8.4%, with the majority due to mortality from comandra blister rust. One-fifth of estimated volume loss was provisionally attributed to growth reductions among live western gall rust infected pine.


1996 ◽  
Vol 128 (2) ◽  
pp. 177-186 ◽  
Author(s):  
Cameron R. Currie ◽  
John R. Spence ◽  
W. Jan A. Volney

AbstractThe life cycle, phenology, and abundance of Epuraea obliquus Hatch was studied near Hinton, Alberta. Most of the life cycle occurs on galls of Endocronartium harknessii (J.P. Moore) Y. Hiratsuka (western gall rust) infecting lodgepole pine (Pinus contorta Dougl. var latifolia Engelm.). Both adults and larvae feed on the spores of the fungus. Individuals of this beetle were found on most galls sampled. Adults overwinter in the soil. They emerge in the spring to seek out and colonize galls. Eggs are laid on the surface of galls, mainly under the periderm, and larvae feed on the fungus, developing through three larval instars. Larvae in the last instar drop from galls to pupate in the soil. Adults leave the soil in late summer and return to feed on inactive galls before overwintering in the soil. The phenology of E. obliquus is closely synchronized with the timing of rust sporulation and the impact of beetle feeding may be an important natural control of western gall rust.


1999 ◽  
Vol 77 (7) ◽  
pp. 1035-1043 ◽  
Author(s):  
Rong-Cai Yang ◽  
Zhihong Ye ◽  
Yasu Hiratsuka

Lodgepole (Pinus contorta Dougl. ex Lound.) and jack (Pinus banksiana Lamb.) pines occur sympatrically and hybridize in central and northwestern Alberta, providing opportunities for studying unique ecological and evolutionary interactions. We conducted a greenhouse inoculation experiment to investigate interactions between 40 populations of lodgepole and jack pines and their putative hybrids across this hybrid zone and two sources of the western gall rust fungus, Endocronartium harknessii (J.P. Moore) Y. Hiratsuka, one from lodgepole pine and the other from jack pine. Rust susceptibility and height were assessed when the seedlings were 6 months and 1 year old. Lodgepole pine and the hybrids were significantly more susceptible to the rust infection than jack pine. Jack pine grew significantly faster than the hybrids and lodgepole pine. In addition, the seedlings infected with spores from lodgepole pine grew significantly slower than those with spores from jack pine. While the overall rust scores indicated that spores from lodgepole pine was more virulent to the hosts than those from jack pine, both spore sources were better adapted to their own host species, causing significant spore source × host group interactions. However, such host specificity in the western gall rust is far from stabilized (equilibrium) because of continued gene exchanges among the two parental species and their hybrids.Key words: Pinus contorta - Pinus banksiana complex, western gall rust, natural hybridization, coevolutionary genetics.


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